In the end your bin folder will have the .exe binaries with a name
like godot.uwp.opt.debug.32.x86.exe (with variations for each
target/arch).

Copy one of these to misc/dist/uwp_template inside the Godot source
folder and rename the binary to godot.uwp.exe. From the ANGLE source,
under winrt/10/src/Release_%arch% (where %arch% can be Win32,
x64 or ARM), get the libEGL.dll and the libGLESv2.dll,
putting them along with the executable.

Add the files in the uwp_template folder to a ZIP. Rename the resulting
Zip according to the target/architecture of the template:

Move those templates to the [versionstring]\templates folder in Godot
settings path, where versionstring is the version of Godot you have compiled
the export templates for - e.g. 3.0.alpha for the alpha version of Godot 3.
If you don’t want to replace the templates, you can set the “Custom Package”
property in the export window.

If you want to debug the UWP port or simply run your apps without packaging
and signing, you can deploy and launch them using Visual Studio. It might be
the easiest way if you are testing on a device such as a Windows Phone or an
Xbox One.

Within the ANGLE source folder, open templates and double-click the
install.bat script file. This will install the Visual Studio project
templates for ANGLE apps.

If you have not built Godot yet, open the winrt/10/src/angle.sln solution
from the ANGLE source and build it to Release/Win32 target. You may also need
to build it for ARM if you plan to run on a device. You can also use MSBuild if
you’re comfortable with the command line.

Create a new Windows App project using the “App for OpenGL ES
(Windows Universal)” project template, which can be found under the
VisualC++/Windows/Universal category.

This is a base project with the ANGLE dependencies already set up. However, by
default it picks the debug version of the DLLs which usually have poor
performance. So in the “Binaries” filter, click in each of the DLLs there
and in the “Properties” window and change the relative path from
Debug_Win32 to Release_Win32 (or Release_ARM for devices).

In the same “Binaries” filter, select “Add > Existing Item” and point to the
Godot executable for UWP you have. In the “Properties” window, set “Content”
to True so it’s included in the project.

Right-click the Package.appxmanifest file and select “Open With… > XML
(Text) Editor”. In the Package/Applications/Application element, replace
the Executable attribute from $targetnametoken$.exe to
godot.uwp.exe (or whatever your Godot executable is called). Also change
the EntryPoint attribute to GodotUWP.App. This will ensure that
the Godot executable is correctly called when the app starts.

Create a folder (not a filter) called game in your Visual Studio project
folder and there you can put either a data.pck file or your Godot project
files. After that, make sure to include it all with the “Add > Existing Item”
command and set their “Content” property to True so they’re copied to the
app.

To ease the workflow, you can open the “Solution Properties” and in the
“Configuration” section untick the “Build” option for the app. You still have
to build it at least once to generate some needed files, you can do so by
right-clicking the project (not the solution) in the “Solution Explorer” and
selecting “Build”.

Now you can just run the project and your app should open. You can also use
the “Start Without Debugging” option from the “Debug” menu (or press Ctrl + F5) to make it
launch faster.